Most marine craft have water based propulsion and water based control surfaces. However, with increased speeds of marine craft this is no longer sufficient. Aircraft-like control surfaces are required especially at very high speeds where roll and pitch of the craft become extremely important for safety purposes.
Air based propulsion also greatly enhances safety and comfort especially in rougher seas. When a normal water propelled marine craft powers over a wave such that it is completely out of the water, the water based propulsion no longer propels the craft and the craft invariably hits the next wave quite hard. This makes marine based travel quite uncomfortable. However, it should be noted that at extremely high speeds it is outright dangerous. With the addition of air based propulsion and aircraft-like surface controls, this situation changes dramatically. Air based propulsion allows continually effective propulsion for high speed craft. And when combined with aircraft-like three axis control surfaces allow this marine craft to safely maneuver over waves at high speed.
A high speed water craft with air based propulsion and control provides additional benefits in river type environments having a naturally shallow draft and being able to shoot rapids very easily. Such a high speed craft in closed waters requires a very specialised hull; one that is stable at high speeds, hydroplanes efficiently and one that safely allows extreme maneuverability.
Almost all airboats have a square shaped bow. This square bow allows the airboats of prior art to go through marshland but is not suitable for high speed marine operation.